The present invention relates generally to magnetic resonance imaging (MRI), and more particularly to a MRI pulse sequences employing steady-state free precession.
MRI pulse sequences that take advantage of steady-state free precession (SSFP), e.g. Siemens' “True-FISP”, General Electric's “FIESTA”, and Phillip's “Balanced FFE”, allow fast imaging without excessive saturation of signals. In practice, SSFP is extremely useful for rapid imaging with relatively high signal-to-noise ratio of fluids such as blood. However, these sequences are inherently sensitive to static magnetic field inhomogeneity. In particular, inhomogeneity tends to create curvilinear regions of signal void in the FIESTA image generally appearing as black lines or voids, potentially obscuring areas of interest or mimicking pathology.
A method is needed for MRI with steady-state free precession pulse sequences that is insensitive to static magnetic field inhomogeneity in order to prevent, for example, the creation of these black lines while retaining the needed T2*/T1 contrast and high signal-to-noise ratio provided by SSFP.